The territory of the Haut-Jura Regional Natural Park is covered at 70% by forests of all kinds. There are several dozen of different ones - of hardwoods or conifers with or without sub-floors (shrubs, herbaceous plants, etc.) - but all are said to be 'secondary', which means that they have known the intervention, in varying degrees, of man who derives an income from them. Primary forests, in contrast, are rare ecosystems that have never known any human intervention.